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Top 10 JavaScript Hack for Optimized Performance

Website development *JavaScript *

JavaScript has been ruling the tech arena for more than two decades and helping developers simplifying complex tasks. It allows developers to implement complex task web pages in a most simplified manner. For most of the developers minified JavaScript file is the common phenomena while very few developers may be aware of Optimized JavaScript code. While meeting through many Javascript developers, I have come to know that Optimized JavaScript code is something that confuses developers, some of them might be doing it, but they are not aware of this.

What is an Optimized JavaScript Code

When combinations of uniquely programmed logics along with small hacks utilized to enhance performance and speed is known as Optimized JavaScript code. Optimization not only optimizes performance and speed but also saves maximum development time. When you save time, you save some bucks as well.

So, I am here with some useful and fruitful hacks to help developers optimize performance, enhance speed and save time. Hope, you like the article and after going through it, you may utilize the best of Optimized JavaScript code.

1.    Make JS code Leaner with Combining Javascript Modules & Minifying JS Files

Leaner code make standardized code format, which helps both developers and applications by giving more readability. That is possible when you combine the JavaScript modules and minifies the JS files. Though a minified version of the code may, sometimes, be difficult to read and understand, you will get coding leaner and optimized for sure. When you have a minified source, it helps you in many ways. For example, it can reduce the page load time, remove line breaks, additional spaces, comments, and much more. These benefits are possible as the minified source shrinks file sizes.

Optimization is also a kind of JavaScript minification, which play a very crucial role not only in removing and deleting unnecessary things such as spaces, commas, etc. but also helps developers do away with unnecessary code blocks. Here are some of the significant tools and library which help you minify the code are;

  • Google Closure Compiler
  • UglifyJS
  • Microsoft AJAX Minifier

When you have larger JavaScript file, it affect page performance such as take time to load page and impact on speed while compressing or minifying code will resolve the issue smartly.

2.    Using Scope in JavaScript is Good Step Forward

Reducing dependency on global variables and closures is yet another way to enhance performance and speed of the applications and that is possible using a JavaScript Scope named 'this'. Yes, 'this' helps developers write asynchronous code with callbacks. However, another scope like 'with' should be avoided as it drags down the performance of the application by modifying the scope chain.

init: function(name) {
this.name = name;
do: function(callback) {
var bob = new Car('Aventador');
bob.do(function() {
alert(this.name); // 'Aventador' is alerted because 'this' was rewired

3.    Utilizing Array Filter

Using Array filter helps developers filter out all elements from the array pool. It is a method which removes the elements which pass through testing. In short, the method creates an array which creates a callback function for not-required elements.

Let's understand how it works through this example.

schema = schema.filter(function(n) {
return n
Output:   ["hi","ilove javascript", "goodbye"]

4.    Replace Function String to Replace the Values

There is a function 'String.replace() which help developers replace strings using the functions. For example;

  • To replace string, use 'String' and 'Regex'
  • To replace all strings, use function 'replaceAll()' function
  • Use /g at the end if you are using 'Regex'

Let's get understand this from the example given below;

var string = "login login";  
console.log(string.replace("in", "out")); // "logout login"  
console.log(string.replace(/in/g, "out")); //"logout logout"

5.    Debugging Using Breakpoints and Console

Utilizing breakpoints and debugging points, you can filter outsource of error by setting multiple barriers. Here's how you can do this;

You can call the next function using F11 and resume script execution using F8.

Using console, developers can easily check the dynamic values created by the function and what is the output.

6.    Do Away with Unused Components from JavaScript Library

During the course of development, you may need libraries like jQuery UI or jQuery Mobile, which come up with loads of components. So, you need to decide which components you want to be loaded. You can do this while downloading the libraries.

7.    Using HTTP/2 can make a Difference

Using the latest version of HTTP protocol can make a huge difference and provide helping hand in enhancing JavaScript performance. Currently, HTTP protocol uses HTTP/2 as its latest version and it utilizes multiplexing which enables multiple requests and responses which can work at the same time. HTTPS has all the features of HTTP/2 and therefore, it can also be a great option to move with.

8.    Delete / Empty in an Array Using 'length'

Using 'length' you can resize the file by deleting and emptying elements in the array. You need to use the following keyword, 'array.length'.

Let's take a look at the example here;

array.length = n

Such as;

var array = [1, 2, 3, 4, 5, 6];
console.log(array.length); // 6
array.length = 3;</strong>
console.log(array.length); // 3
console.log(array); // [1,2,3]

Similarly, if you want empty the array, you need to use;

Array.length = 0;.

Take a look at the example here;

var array = [1, 2, 3, 4, 5, 6];
array.length = 0;
console.log(array.length); // 0
console.log(array); // []

The technique is very useful in resizing the file and enhancing the JavaScript performance.

9.    Apply Switch Case over If / Else

Using the Switch case over if/else enables developers to shorten execution time. Using if/else makes testing lengthier. Therefore, you need to evaluate it.

10. Caching DOM Object

Using script repeatedly accesses certain DOM objects. For example, the object "document.images" will be looked up two times for each loop and if you have 10 such images, then there will be 20 calls. Let's look at the example here.

<script type”text/javascript”>
for (var i = 0; i &lt;document.images.length; i++) 

However, you can look for the alternative which will improve the application performance by reducing the browser loading time. Here's how it happens;

<script type=”text/javascript”>
Var domImages = document.images;
For (var i=0; i&lt;domImages.length’ i++)
domImages[i].src = “image.gif”;


These are the top 10 JavaScript hacks, which will help you improve application performance. However, if you believe that the number of tips I have explained here completes the list, then you are mistaken. There are plenty of similar hacks are there which you apply to gain maximum benefits in terms of performance, speed, and time. Further, it depends on frameworks you used. Here is a list of Top Javascript Frameworks to be used as modern front end development

Furthermore, I would love to learn from you. If you come across any such hack/s, then never hesitate to email us. You can do this by sending your message and knowledge through various communication channels such through Skype, WhatsApp, or Contact Us.

Tags: Javascriptjavascript hacks
Hubs: Website development JavaScript
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